Optical phase modulation is employed to control the phase of a light signal in a wide range of telecommunication and sensing applications. Non-limiting fields of application include coherent optical communications using, for example, the phase-shift key (PSK) modulation format or its derivatives; fiber optics and integrated photonics; fiber optic gyroscope sensors and other interferometric-based sensors; lidar and other optical remote sensing techniques; and active mode locking of lasers. Common types of phase modulators are thermo-optic and electro-optic phase modulators, which achieve phase modulation of a light signal via, respectively, thermally and electrically controlled changes in the refractive index of the medium in which the light signal travels. While these types of optical phase modulators have proven useful in some applications, they also have some drawbacks and limitations, for example in terms of achieving control over the harmonic content of the phase-modulated signal. Challenges therefore remain in the field of optical phase modulation.